U.S. patent application number 12/150214 was filed with the patent office on 2008-10-30 for method for detecting parking area by using range sensor.
Invention is credited to Dong-suk KIM.
Application Number | 20080266139 12/150214 |
Document ID | / |
Family ID | 39777669 |
Filed Date | 2008-10-30 |
United States Patent
Application |
20080266139 |
Kind Code |
A1 |
KIM; Dong-suk |
October 30, 2008 |
Method for detecting parking area by using range sensor
Abstract
Disclosed is a method for detecting a parking space by using a
range sensor, which includes the steps of: (a) collecting, by a
parking environment recognition control unit, distance data in a
predetermined period by using the range sensor according to a
user's selection and mapping the collected distance data on a
coordinates system based on a parking space searching vehicle; (b)
classifying the collected distance data into short distance data
and long distance data; (c) calculating parking-available distance
data which is a horizontal movement distance of an interval where
the long distance data is collected from when the long distance
data starts to be collected; (d) checking if the parking space
exists based on the calculated parking-available distance data; (e)
stopping the parking space searching vehicle by controlling an
active braking apparatus or recommending a driver to stop the
parking space searching vehicle by means of a voice and alarm
sounds when it has been checked in steps (d) that the parking space
exists; and (f) generating the distance data, which has been mapped
based on the parking space searching vehicle in step (a) and has
been classified into the short distance data and the long distance
data in step (b), as a parking environment map. Distance data
obtained by a range sensor is mapped on a coordinate system based
on own vehicle, and the obtained distance data is classified into
short distance data and long distance data, and it is determined if
an available parking area exists so as to be provided to a driver.
Therefore, an available parking area is further rapidly and
accurately detected so as to allow the driver to park his/her
vehicle in a convenient manner.
Inventors: |
KIM; Dong-suk; (Siheung-si,
KR) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Family ID: |
39777669 |
Appl. No.: |
12/150214 |
Filed: |
April 24, 2008 |
Current U.S.
Class: |
340/932.2 |
Current CPC
Class: |
B62D 15/027
20130101 |
Class at
Publication: |
340/932.2 |
International
Class: |
B60Q 1/48 20060101
B60Q001/48; G08G 1/14 20060101 G08G001/14 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 27, 2007 |
KR |
2007-0041388 |
Claims
1. A method for detecting a parking space by using a range sensor,
comprising the steps of: (a) collecting, by a parking environment
recognition control unit, distance data in a predetermined period
by using the range sensor according to a user's selection and
mapping the collected distance data on a coordinates system based
on a parking space searching vehicle; (b) classifying the collected
distance data into short distance data and long distance data; (c)
calculating parking-available distance data which is a horizontal
movement distance of an interval where the long distance data is
collected from when the long distance data starts to be collected;
(d) checking if the parking space exists based on the calculated
parking-available distance data; (e) stopping the parking space
searching vehicle by controlling an active braking apparatus or
recommending a driver to stop the parking space searching vehicle
by means of a voice and alarm sounds when it has been checked in
steps (d) that the parking space exists; and (f) generating the
distance data, which has been mapped based on the parking space
searching vehicle in step (a) and has been classified into the
short distance data and the long distance data in step (b), as a
parking environment map.
2. The method for detecting parking space by using a range sensor
as claimed in claim 1, wherein, in step (b), a width of the parking
space searching vehicle is set as a critical value, the distance
data is classified as long distance data in a case where a
difference value between current collected distance data and just
previously collected distance data is a positive number and the
positive number exceeds the critical value, the distance data is
classified as short distance data in a case where a difference
value between current collected distance data and the just
previously collected distance data is a negative number and an
absolute value of the negative number exceeds the critical value,
the distance data is classified as the short distance data in a
case where a difference value between the current collected
distance data and the just previously collected distance data does
not exceed the critical value although the difference value is a
positive number, and the distance data is classified as the long
distance data in a case where the absolute value of a difference
value between the current collected distance data and the just
previously collected distance data does not exceed the critical
value although the difference value is a negative number.
3. The method for detecting parking space by using a range sensor
as claimed in claim 1, wherein, in step (c), when the long distance
data is collected while the distance data is collected, a time
period between a time point where the long distance data starts to
be collected and a time point just before the short distance data
starts to be collected and movement velocity of the parking space
searching vehicle are stored, respectively, and then
parking-available distance data is calculated based on the time
period and the movement velocity.
4. The method for detecting parking space by using a range sensor
as claimed in claim 1, wherein, in step (d), a value obtained by
adding a predetermined length to a length of the parking space
searching vehicle is set as a critical value of the
parking-available distance data so as to check if the parking space
exists.
5. The method for detecting parking space by using a range sensor
as claimed in claim 1, wherein, in step (f), average values of an X
coordinate and a Y coordinate of each short distance data, which is
collected before and after the long distance data is collected, are
calculated so that lines connecting between the average values of
the X coordinate and the Y coordinate of each short distance data
are set as a front parking side boundary line and a rear parking
side boundary line, while considering a recognition error and a
control margin at each boundary point of the short distance data
and the long distance data, lines perpendicular to the front
parking side boundary line and the rear parking side boundary line,
respectively, are defined as a parking front boundary line and a
parking rear boundary line, respectively, and the average values of
the X coordinate and the Y coordinate of the long distance data are
calculated so that a line connecting between the average values of
the X coordinate and the Y coordinate of the long distance data is
marked on a parking environment map.
6. The method for detecting parking space by using a range sensor
as claimed in claim 1, further comprising the step of displaying
the generated parking environment map on a monitor included in the
parking space searching vehicle in such a manner that the parking
environment map is reflected on an image inputted through a rear
camera included in the parking space searching vehicle.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional application claims priority under 35
U.S.C .sctn.119(a) on Patent Application No. 10-2007-0041388 filed
in Korea on Apr. 27, 2007, the entire contents of which are hereby
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a method for detecting a
parking space by using a range sensor, and more particularly to a
method for detecting a parking space by using a range sensor, in
which distance data obtained by a range sensor is mapped on a
coordinate system based on a vehicle having the range sensor, the
obtained distance data is classified into short distance data and
long distance data, and it is determined if an available parking
area exists so as to be provided to a driver.
[0004] 2. Description of the Prior Art
[0005] A semiautomatic parking system is an apparatus in which a
steering operation required for a parking process is automated so
as to improve convenience for a driver. In general, drivers are
much interested in a parking auxiliary system. Therefore, main
vehicle manufacturers and component auto parts makers have
developed various types of parking auxiliary systems.
[0006] Such a semiautomatic parking system can include a
recognizing unit and a control unit. The recognizing unit performs
a function for obtaining information regarding an available parking
area through a parking environment recognizing algorithm operation
by means of an environment information obtaining sensor, such as a
vision sensor or a range sensor (ultrasonic wave, laser, etc). The
control unit performs a control operation so that an active
steering apparatus is controlled based on a result obtained by the
operation in the recognizing unit so as to allow a vehicle to be
parked at a recognized parking area.
[0007] In order to perform a parallel parking function of the
semiautomatic parking system, it is necessary to extract
information regarding an available parking space by obtaining
information regarding an empty parking area between vehicles parked
in a row at a side of a road. Particularly, the semiautomatic
parking system has to extract relative coordinates between own
vehicle and the available parking space.
[0008] Therefore, it is required to develop a technique for
recognizing an available parking space, which can further
accurately and rapidly determine and recognize a target parking
position through only a simple operation performed by the
driver.
SUMMARY OF THE INVENTION
[0009] Accordingly, the present invention has been made to solve
the above-mentioned problems occurring in the prior art, and the
present invention provides a method for detecting a parking area by
using the range sensor, in which distance data obtained by a range
sensor is mapped on a coordinate system based on a vehicle having
the range sensor, the obtained area data is classified into short
distance data and long distance data, and it is determined if an
available parking area exists so as to be provided to a driver.
[0010] In accordance with an aspect of the present invention, there
is provided a method for detecting a parking space by using a range
sensor, which includes the steps of; (a) collecting, by a parking
environment recognition control unit, distance data in a
predetermined period by using the range sensor according to a
user's selection and mapping the collected distance data on a
coordinates system based on a parking space searching vehicle: (b)
classifying the collected distance data into short distance data
and long distance data; (c) calculating parking-available distance
data which is a horizontal movement distance of an interval where
the long distance data is collected from when the long distance
data starts to be collected; (d) checking if the parking space
exists based on the calculated parking-available distance data; (e)
stopping the parking space searching vehicle by controlling an
active braking apparatus or recommending a driver to stop the
parking space searching vehicle by means of a voice and alarm
sounds when it has been checked in steps (d) that the parking space
exists; and (f) generating the distance data, which has been mapped
based on the parking space searching vehicle in step (a) and has
been classified into the short distance data and the long distance
data in step (b), as a parking environment map.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The above and other objects, features and advantages of the
present invention will be more apparent from the following detailed
description taken in conjunction with the accompanying drawings, in
which:
[0012] FIG. 1 is a view illustrating the movement of a vehicle
while a parking space is detected by an area sensor according to an
exemplary embodiment of the present invention;
[0013] FIG. 2 is a flow chart illustrating a process for detecting
a parking space by means of an area sensor according to an
exemplary embodiment of the present invention; and
[0014] FIG. 3 is a schematic view illustrating a screen where a
parking space detected by using an area sensor is display to a
driver according to an exemplary embodiment of the present
invention.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0015] FIG. 1 is a view illustrating the movement of a vehicle
while a parking space is detected by an area sensor according to an
exemplary embodiment of the present invention.
[0016] A parking space searching vehicle 100 according to an
embodiment of the present invention includes area sensors 102
mounted on both side surfaces of the vehicle.
[0017] In order to make it easy to understand the present
invention, it is assumed that an available parking space, at which
the parking space searching vehicle 100 can be parked, exists
between a first parked vehicle 110 and a second parked vehicle 120,
which are parked at a parallel space.
[0018] The parking space searching vehicle 100 detects a distance
by means of a range sensor 102 so as to search a parking space.
[0019] Distance data collected by the range sensor 102 is
classified into short distance data 130 obtained due to an obstacle
(the first parking vehicle 110 or the second parking vehicle 120 in
the present invention) and long distance data 140 obtained due to
empty space without an obstacle (an empty space between the first
parking vehicle 110 and the second parking vehicle 120 in the
present invention).
[0020] In the present invention, distance data collected by the
range sensor 102 is classified into two classes in such a reference
manner that when width of the parking space searching vehicle 100
is determined as a critical value, the distance data is classified
as long distance data 140 in a case where a difference value
between current collected distance data and just previously
collected distance data is a positive number, and the positive
number exceeds the critical value, and the distance data is
classified as short distance data 130 in a case where a difference
value between current collected distance data and just previously
collected distance data is a negative number and an absolute value
thereof exceeds the critical value.
[0021] Also, the distance data is classified as short distance data
130 in a case where a difference value between the current
collected distance data and just previously collected distance data
does not exceed the critical value although the difference value is
a positive number, and the distance data is classified as long
distance data 140 in a case where the absolute value of a
difference value between current collected distance data and just
previously collected distance data does not exceed the critical
value, although the difference value is a negative number.
[0022] When the long distance data 140 is collected while distance
data is collected by the range sensor 120, a parking environment
recognition control unit of the parking space searching vehicle 100
stores the time period between a time point where the long distance
data 140 starts to be collected and a time point just before the
short distance data 130 starts to be collected and movement
velocity of the parking space searching vehicle 100, respectively,
and then calculates parking-available distance data 150 base on the
stored period of time and the movement velocity while the long
distance data 140 is collected.
[0023] For example, if it is assumed that the time period between a
time point where the long distance data 140 starts to be collected
and a time point just before the short distance data 130 is
collected is five seconds, and an average value of movement
velocity of the parking space searching vehicle 100 is 5 km/h
during the time period between the time point where the long
distance data 140 starts to be collected and the time point just
before the short distance data 130 is collected, a distance where
the parking space searching vehicle 100 moves for one second is 1.3
m during the time period between the time point where the long
distance data 140 starts to be collected and the time point just
before the short distance data 130 is collected, so that a distance
where the parking space searching vehicle 100 moves while the long
distance data 140 is collected is 6.5 m, and then this distance of
6.5 m becomes parking-available distance data 150.
[0024] In order to allow the parking space searching vehicle 100 to
be parked, the parking-available distance data 150 calculated in
the parking environment recognition control unit has to be a
distance longer at a certain degree than the length of the parking
space searching vehicle 100. Therefore, a critical value of the
parking-available distance data 150 is a value obtained by adding a
predetermined length to the length of the parking space searching
vehicle 100. That is, the critical value can be changed according
to the length of the parking space searching vehicle 100.
[0025] FIG. 2 is a flow chart illustrating a process for detecting
a parking space by means of the area sensor according to an
exemplary embodiment of the present invention.
[0026] In order to achieve parking, the parking environment
recognition control unit of the parking space searching vehicle 100
has to collect distance data so as to search for an available
parking area in a parallel parking space by means of a range sensor
102. Therefore, the parking environment recognition control unit of
the parking space searching vehicle 100 starts to collect distance
data by using the range sensor 102 at a place, at which parking is
intended to be achieved, in step S200.
[0027] The time period of collecting distance data, which is
detected and collected from the range sensor 102, can be changed
according to the user's selection, and it is preferable that
distance data is collected in a predetermined time period (e.g. a
period of 0.1 second).
[0028] When distance data is collected from the range sensor 102 in
a predetermined period, the parking environment recognition control
unit of the parking space searching vehicle 100 maps the collected
distance data on a coordinate system based on the parking space
searching vehicle 100 in step S202.
[0029] Distance data collected while the parking space searching
vehicle 100 moves does not reflect the location of the parking
space searching vehicle 100, which is changed according to movement
velocity or steering operation whenever the data is measured.
Therefore, it is impossible to grasp relative location respective
to the parking space searching vehicle 100.
[0030] For example, in a case where the parking space searching
vehicle 100 collects distance data from a location A by using the
range sensor 102, the collected distance data does not reflect the
location of the parking space searching vehicle 100 when the
parking space searching vehicle 100 goes far away from the first
parking vehicle 110 at a less degree or near to the first parking
vehicle 110 at a less degree due to steering operation of the
driver. Therefore, the parking space searching vehicle 100
periodically performs pose estimation of own vehicle (the parking
space searching vehicle 100 in the present invention) so as to
calculate coordinates of obtained distance data. At this time, the
parking space searching vehicle 100 receives data regarding
movement of own vehicle, such as a steering angle, velocity of
wheels, a yaw, a LG sensor, etc. and calculates the location of the
parking space searching vehicle 100 through periodical updating of
the above received data. In step S202 in the present invention, the
parking environment recognition control unit converts movement data
of the parking space searching vehicle 100, which has been
calculated by performing pose estimation, and distance data, which
has been synchronized and received, to a coordinate system of the
own vehicle so that the parking environment recognition control
unit maps the distance data on a coordinate system based on the
parking space searching vehicle 100 in each period.
[0031] A technique for estimating the location of a vehicle, in
which the technique is performed, is known for those skilled in the
art. Therefore, the description of the technique will be omitted
herein.
[0032] The parking environment recognition control unit classifies
the distance data mapped on the coordinate system based on the
parking space searching vehicle 100 in step S202 into short
distance data 130 and long distance data 140 in step S204.
[0033] In the present invention, distance data collected by using
the range sensor 102 is classified into two classes, i.e. short
distance data 130, which is data regarding a distance from an
obstacle (the first parking vehicle 110 or the second parking
vehicle 120 in the present invention) to the parking space
searching vehicle 100, and long distance data 140, which is data
regarding a distance from empty space without an obstacle (empty
space between the first parking vehicle 110 and the second parking
vehicle 120 in the present invention) to the parking space
searching vehicle 100.
[0034] In step S204, only distance data, which is collected in
regardless of a process for mapping the distance data collected in
step S202 on the coordinate system based on the parking space
searching vehicle 100, is used. Therefore, it is possible to
simultaneously perform step S204 and step S202.
[0035] The parking environment control unit calculates
parking-available distance data 150, which is a horizontal movement
distance of an interval where the long distance data 140 is
collected, from the time point when the long distance data 140 of
the distance data classified in step S204 starts to be
collected.
[0036] When the long distance data 140 is collected while distance
data is collected by using the range sensor 102, the parking
environment recognition control unit of the parking space searching
vehicle 100 stores a time period from a time point when the long
distance data 140 starts to be collected to a time point just
before the next short distance data 130 starts to be collected and
movement velocity of the parking space searching vehicle 100,
respectively. Then, the parking environment recognition control
unit calculates parking-available distance data 150 while the long
distance data 140 is collected based on the stored time period and
the movement velocity.
[0037] Base on the parking-available distance data 150, it is
checked if an available parking space enough to allow the parking
space searching vehicle 100 to be parked exists in step S208.
[0038] In a case where it has been checked in step S208 that an
available parking space enough to allow the parking space searching
vehicle 100 to be parked exists, the parking environment
recognition control unit stops the parking space searching vehicle
100 by controlling an active braking apparatus or recommends a
driver to stop the parking space searching vehicle 100 by means of
a voice, alert sounds, a pilot lamp, etc. in step S210.
[0039] The parking environment recognition control unit maps the
collected distance data based on the parking space searching
vehicle 100 in step S202, and generates the distance data, which
has been classified into the short distance data 130 and the long
distance data 140 in step S204, as a parking environment map in
step S212.
[0040] After step S212, the parking space searching vehicle 100 is
parked by a steering operation of a driver, an automatic parking,
or a semiautomatic parking. Herein, techniques of automatic parking
and semiautomatic parking are known to those skilled in the art, so
descriptions of these will be omitted.
[0041] Step S212 will be described together with FIG. 3.
[0042] FIG. 3 is a schematic view illustrating a screen where a
parking area detected by an area sensor is displayed to a driver
according to an exemplary embodiment of the present invention.
[0043] The parking environment recognition control unit of the
parking space searching vehicle 100 calculates average values of an
X coordinate and a Y coordinate of the short distance data 130 in
front and rear directions of the available parking space 350, and
detects a front parking side boundary line 320 and a rear parking
side boundary line 322 as lines connecting between calculated
average values of the X coordinate and the Y coordinate of the
short distance data 130. The parking environment recognition
control unit also defines lines perpendicular to the front parking
side boundary line 320 and the rear parking side boundary line 322
as a parking front boundary line 340 and a parking rear boundary
line 342, respectively, while considering a recognition error and a
control margin at each boundary point 330 between the short
distance data 130 and the long distance data 140.
[0044] A line as an interval where the long distance data 140 is
collected between the front parking side boundary line 320 and the
rear parking side boundary line 322, in which collected average
values of the X coordinate and the Y coordinate of the long
distance data 140 are calculated, and then the calculated average
values of the x coordinate and the Y coordinate of the long
distance data 140 are connected with each other, is marked on a
parking environment map.
[0045] A space having a plan of a square shape, which is formed in
such a manner that a line connecting between each boundary point
330 of the short distance data 130 and the long distance data 140,
a line connecting between the calculated average values of the X
coordinate and the Y coordinate of the long distance data 140, the
parking front boundary line 340, and the parking rear boundary line
342 meet each other, becomes an available parking space. In order
to allow the parking space searching vehicle 100 to be parked at
the square space, the available parking area 350 is displayed on a
monitor 360 included in the parking space searching vehicle
100.
[0046] When the available parking area is displayed on the monitor
360, it is preferable that a view image converted through an image
process is displayed, or the parking environment map is reflected
on an image inputted through a rear camera 310 included in the
parking space searching vehicle 100 so as to be displayed.
[0047] According to the present invention described above, distance
data obtained by a range sensor is mapped on a coordinate system
based on own vehicle, and the obtained distance data is classified
into short distance data and long distance data, and it is
determined if an available parking area exists so as to be provided
to a driver. Therefore, an available parking area is further
rapidly and accurately detected so as to allow the driver to park
his/her vehicle in a convenient manner.
[0048] Although an exemplary embodiment of the present invention
has been described for illustrative purposes, those skilled in the
art will appreciate that various modifications, additions and
substitutions are possible, without departing from the scope and
spirit of the invention as disclosed in the accompanying claims.
While the present invention has been shown and described with
reference to certain exemplary embodiments thereof, it will be
understood by those skilled in the art that various changes in form
and details may be made therein without departing from the spirit
and scope of the invention as defined by the appended claims.
Therefore, an exemplary embodiment of the present invention has not
been described for limiting purposes so that the scope and spirit
of the invention may not limited by the exemplary embodiment
thereof. Accordingly, the scope of the invention is not to be
limited by the above embodiments but by the claims and the
equivalents thereof.
* * * * *